Notebook Sea Algae Cyanotype

The cyanotype, a stable photosensitive emulsion based on iron and cyanide salts, was invented by the astronomer and physicist John Herschel (1792-1871), who introduced it to Anna Atkins (1799-1871) in 1842. The following year, she applied this process to dried macroalgae from her collections, which she placed directly on papers treated in this way. Her delicate prints would fill no fewer than three volumes spread over a decade. Atkins would repeat the exercise with Cyanotypes of British and Foreign Ferns, Cyanotypes of British and Foreign Flowering Plants and Ferns.